He signed a one-year deal with Brighton & Hove Albion for the following campaign, but featured little and joined League One club Notts County on loan for the final third of the season.

He was released by mutual consent halfway through to enable him to return to Northern Ireland, where he signed a one-year contract with NIFL Premiership club Glenavon.

He made his first-team debut in the Football League Trophy on 16 October 2001 and his potential prompted his signing to the Spotland club on a three-and-a-half-year professional contract in December 2001.

After Rochdale manager Steve Parkin informed him that he was to be released, McCourt headed for another trial, this time with Scottish Premier League outfit Motherwell.

As the club ran into financial difficulty, mainly due to the costs surrounding the building of Tallaght Stadium, Rovers were forced to place all players except McCourt on the transfer list.

After seven goals in 17 appearances,[6] and following interest from Bristol City and Queens Park Rangers, the club, in dire need of funds, decided to sell McCourt.

The lure of joining Celtic, the club he had supported as a boy, persuaded McCourt to move to Glasgow and, on 19 June 2008, he signed for a fee of £200,000[7] after agreeing a three-year contract.

[14] On 23 September 2009, McCourt opened his goalscoring account for Celtic with a memorable goal in a League Cup match at Falkirk, in which he beat five defenders before chipping the ball over goalkeeper Bobby Olejnik.

On 24 January 2010, McCourt bagged his second league goal for Celtic against St Johnstone after a mazy run and finish into the top right hand corner, from just inside the penalty box.

[17] Premier League newcomers Blackpool expressed an interest in McCourt following his performances throughout the 2009–10 season, prompting Celtic to offer him an improved contract, which he duly signed.

[24] McCourt was mainly used as a late substitute over the course of the next two seasons, failing to score a single goal, though he was part of the Celtic team that won both the 2011–12 and 2012–13 SPL titles, as well as the 2013 Scottish Cup.

[27] On 22 August 2013, McCourt signed for Championship club Barnsley, managed by his former Rochdale teammate David Flitcroft, on a one-year deal.

One goal, which opened the scoring in Barnsley's 3–2 victory over Middlesbrough, saw McCourt guide the ball into the box and take out six opposition players, before finishing past the goalkeeper from the six-yard line.

[37] McCourt made 25 appearances, scoring one goal during the 2015–16 season,[38] but was released from his contract one year early on 24 May 2016 to enable him to return to Northern Ireland.

[41] His league debut came one week later in a 4–0 home win over Carrick Rangers on the opening day of the 2016–17 season, but was substituted in the 43rd-minute due to an injury.

In June 2018, it was announced that McCourt would retire from playing at the end of the season to take up a role as head of youth structures at Derry City.

[52] In April 2002, Northern Ireland manager Sammy McIlroy handed McCourt his senior international debut against Spain in a friendly at Windsor Park, which his team lost 5–0.

He scored his first international goals with two solo efforts, as he helped Northern Ireland to a 4–0 victory over the Faroe Islands in a 2012 European Championship qualification match on 10 August 2011.

[56] The second goal, which saw him dribble the ball for 40 yards past four players and finish with a close-range chip over the opposition goalkeeper, was described by the Belfast Telegraph as "one of the best ever witnessed" for Northern Ireland.

[62] Leroy has previously worked as a scout for various English and Scottish clubs and is a FIFA registered football agent; his brother Paddy being one of his clients.

[68] The charges were quashed in December 2023, following which his solicitor, Ciarán Shiels, described McCourt's conviction as a "grave miscarriage of justice" and said the former footballer had been "very shabbily treated by the PSNI in this city".